Conventionally, as such stroke-type linear motor actuator, there is known a voice coil motor having permanent magnets and coils (for example, see PL1). The operational principle of the voice coil motor utilizes Fleming's left-hand rule that thrust is generated when current is passed through a coil in a magnetic field created by a permanent magnet. When the alternating is passed through the coil, the coil travels in one-axis direction in the range of the magnetic field of the permanent magnet. As the voice coil motor has features of high-speed movement and lower cost, it is used in various applications such as a speaker, head driving of magnetic disk and spool driving of servo valve.